The 150 series Dual Battery Guide

[rpn]

So I installed my Redarc BCDC1225D into my 2016 VX this week. used a Centrury 95Ah battery and Piranha battery tray. All good so far.

I just wanted to let everyone know about the purpose build bracket i used from Out of Town 4WD Barnsley, NSW. They manufacture a SS bracket that fits between the front grill and radiator, out of the heat of the engine bay. It is designed to suit all Prado 150s from 09 onwards. Cost around $55 plus delivery, or pickup if you live locally. The thing I really like about this bracket is that is has two additional spaces where the Redarc 40AMP Midi fuses can be mounted right next to the BCDC. Very neat indeed. Made my install very easy and I highly recommended the product.

I'll post some photos of the install when I get a chance.

Nice setup, that bracket would make life easier for mounting the DCDC charger.

Ideally though for max protection, the fuses should be located as close as possible to the positive terminal of each battery.

[drivesafe]

Hi Mototrans, as AB has posted, you have not supplied enough info to be able to help you.

Could you post up details of your specific CPAP machine and we can give you some relevant replies that may help you set up for what you need.

Also, if you have any idea, post up your likely drive times between overnight stops.

[Audiobuzz]

I'm not running a camper, but will run work lights off the rack for camping.. and a fridge...The CPAP machine only runs for 8 hours a night and peaks at an exadgerated 5amp on startup before settling back between 1 - 3 amp depending on how hard its working, humidifier setting etc.. so I can manage it to be conservative past startup...

Where are you measuring the current? You say it's a 240v machine so if you're measuring 1-3A at 240V then your maths isn't correct and I suspect you'll need a much bigger battery.

AB

[2016VX]

So I installed my Redarc BCDC1225D into my 2016 VX this week. used a Centrury 95Ah battery and Piranha battery tray. All good so far.

I just wanted to let everyone know about the purpose build bracket i used from Out of Town 4WD Barnsley, NSW. They manufacture a SS bracket that fits between the front grill and radiator, out of the heat of the engine bay. It is designed to suit all Prado 150s from 09 onwards. Cost around $55 plus delivery, or pickup if you live locally. The thing I really like about this bracket is that is has two additional spaces where the Redarc 40AMP Midi fuses can be mounted right next to the BCDC. Very neat indeed. Made my install very easy and I highly recommended the product.

I'll post some photos of the install when I get a chance.

[Mototrans]

DC/DC devices will charge batteries, and in some cases, will do so better than straight off an alternator, but in the vast majority of cases, there are better and cheaper ways to achieve better results, people just need to be made aware of what else is out there.

Hi Gents,

I've been analysing this thread as I'm going to drop a dual battery in my Prado. I need to get this set up right as I need the rear 240v outlet for my CPAP machine..its literally the air that I breathe.

I was thinking of doing the battery tray and second battery with a wire running to the rear and locating a second point above the existing rear 220v outlet to keep the Circuit independent of the car circuit. Is there any benefit to me doing this? Or should I just rely on the existing car circuit and make sure I get the dual battery setup right up front..?

I ran into a 4wd store to buy the bits and pieces only to be told I needed a DCDC Redarc Battery manager and that I should avoid the isolator setup.. my opinion after leaving the store empty handed and confused was that the sales rep was trying to upsell me.. I mean, I'm sure the battery manager is a sophisticated piece of machinery, but it is essentially a glorified battery charger with a bit more flexibility.. (am I wrong or ignorant?)

I'm not running a camper, but will run work lights off the rack for camping.. and a fridge...The CPAP machine only runs for 8 hours a night and peaks at an exadgerated 5amp on startup before settling back between 1 - 3 amp depending on how hard its working, humidifier setting etc.. so I can manage it to be conservative past startup..

If my maths are correct 8 hours x 5 amp = 40 amp hours required.
Running a fridge at 5 amp hours peak load is relatively the same.. so for an overnight stay a 100 amp hour battery should be fine..?


please, I'm happy to hear any suggestions as to how I can get a robust system without the bling..

[Duncan Groenewald]

Brains, I, for one, appreciate getting Drivesafe's view on matters. My impression is he knows what he is talking about and has taken considerable time to share his knowledge and expertise.

Thanks Drivesafe, please keep sharing and thanks for taking the time to do so.

[Rich_150]

I installed an ARB battery tray yesterday and inserted a Century NS70T battery. The valve on the air con pipe was hard up against the battery. I removed the battery and rotated the Z bracket that holds the air con pipe about 5 degrees or so. (I had to drill a new hole for the locator on the bracket). This pushed the aircon pipe over about 5 to 10mm which gave me the clearance I was after. Has anybody else done this? Am I setting myself up for an aircon pipe failure down the track or am I going to get away with it do you think?

[bluprint]

I went with and ARB tray and a Supercharge Amptech D50Z battery + Narva 140A voltage relay + auto fuses.

https://au.pinterest.com/pin/489344315747561601/
https://au.pinterest.com/pin/489344315747561582/
https://au.pinterest.com/pin/489344315747561620/
https://au.pinterest.com/pin/489344315747561616/

[drivesafe]

Hi again mullerwh, if you were to fit one of Leigh’s Booster fuses, you would charge a flat Optima to over 95% in less than an hour and it would be fully charged in well under 2 hours.

But if you have batteries in a caravan or camper trailer, they too would charge much quicker, without the need of a DC/DC device.

DC/DC devices will charge batteries, and in some cases, will do so better than straight off an alternator, but in the vast majority of cases, there are better and cheaper ways to achieve better results, people just need to be made aware of what else is out there.

[mullerwh]

Hi mullerwh, if you have an Optima D34 ( 55Ah ) and it is at 10.5v ( 0% SoC ) a new Prado, with the lower operating voltage will get the battery back over 95% SoC in around 1 hour.

If you use your 25 amp DC/DC device, it will take over 2.5 hours.

In both cases, there is no reason why you can not get that last 5% of charge into the battery.

Even though it will take longer for an alternator to get that last 5%, it will still fully charge the Optima, but because your alternator can get the battery up over 95% much, MUCH sooner than any DC/DC device can, you will still end up with a fully charge battery in around the same time but for a lot less setup cost.

Thanks very much Drivesafe. My 2010 GXL outputs 13.6 constantly with the current isolator setup without the diode/booster. What would the benefit be the of the diode/booster with my current almost constant output of 13.6v?

Time to sell the BCDC1225 or build a battery box

[drivesafe]

Hi mullerwh, if you have an Optima D34 ( 55Ah ) and it is at 10.5v ( 0% SoC ) a new Prado, with the lower operating voltage will get the battery back over 95% SoC in around 1 hour.

If you use your 25 amp DC/DC device, it will take over 2.5 hours.

In both cases, there is no reason why you can not get that last 5% of charge into the battery.

Even though it will take longer for an alternator to get that last 5%, it will still fully charge the Optima, but because your alternator can get the battery up over 95% much, MUCH sooner than any DC/DC device can, you will still end up with a fully charge battery in around the same time but for a lot less setup cost.

Something else to consider.

Say your Optima is flat but you only drive for an hour.

Your alternator will have your battery up over 95% in that time, giving you about 52Ah available for your next stop, but your 25 amp DC/DC device will only have replaced 25Ah at best.

[mullerwh]

Isolator vs BCDC charge times

Please correct me, having gone through the thread and trying put things into perspective, this is what I understand the difference to be between charging via Isolator and Redarc BCDC1225 in terms of time:

Battery 55AH Yellow Top Battery (max current input 40A)

Redarc output 25ah/h Time to charge to 90% of 55AH from 0% = 119 minutes
Isolator output 40ah/h (limited to battery input current) Time to charge to 90% of 55AH from 0% = 83 minutes

Difference in charging time to 90% = 36 minutes (isolator vs BDCD)

The time required to charge for the BCDC to charge the battery from 90% to 100% (additional 5.5Ah) is not known but is possible.
The isolator cannot charge the battery to 100%.

Taking a 50L Waeco CFX quoted consumption of 0.77ah/h the additional 5.5 AH (90%-100% of the battery) would provide for another 7.1 hours of running time.

Questions that remains:
Does higher voltage equals higher amperage output, if so does that mean 40a is not output at 13.6v, or does higher voltage only equate to less charging time?

Some serious assumptions above but comment would be appreciated.

[SimpleSi]

So my plan is (any suggestions appreciated):
Optima D27F $315
ARB Battery tray $120ish?
Kickass VSR $58 (Dual sensing and manual overide)
2-3m (Red) 6B&S to connect the battery +ve terminals (via VSR and 2 x 50Amp fuse/manual reset CB's?)
Solid Kits Dual voltmeter (Prado 150 switch). 6mm auto cable connected to each side of VSR through firewall. -ve connected to body under dash. $65
Disconnect the current 6B&S cable from the relay (not a vsr) and extend to the Aux battery +ve terminal.
Short 6B&S cable (Black) from Aux -ve to body.

Sounds about right? 50A or 100A Fuse or CB at each batterys +ve terminal?
6B&S do the job linking the batteries?

(Edit: I currently have a battery box in the boot running a 47L fridge (2degC). Drove a total of 45mins this morning and when I went to pick up kids at 3pm, the battery (fridge wasn't cycling) sitting at 12.9V. Leighs diode working well ;-)

[LeighW]

You just need to run a separate feed of the existing vsr for the cars aux. If you need to
isolate from the car then you can just disconnect the Anderson plug. Before I installed
my Lithiums that is what I used as all batteries had similar terminal voltages so just
left then connected to share the load, also had the advantage that when parked with
240V available the charger in the van would also charge the cars aux.

As for solar, if I was starting out from scratch I would purchase a good quality MPPT unit that can handle around four solar panels in series. Putting the panels in series gives the MPPT much
more head room to work with and you'll get a lot more current out in overcast conditions etc.

[SimpleSi]

Why just take another feed off the VSR to the aux in the car and try the trailer without the DCDC chargerand see how you get on, as long as you run decent sized cable you should be able to charge the trailer batteries ok without the charger?

I have thought about this, but for the trailer, I'd like the option of 2 x unregulated solar panels, so it's either a decent MPPT controller or IDC25 ($150 vs $280?).
Perhaps I will just run the rear andersons (boot and towbar) off the Aux battery. I believe it is 6B&S all the way to the towbar. If I did it this way, I'd have to put a 2nd VSR in between the Aux battery and trailer batteries. (So once again a DCDC charger would do the job).